More enhancements to ChangeBuilder

pkg/analysis_server/lib/src/utilities/change_builder_core.dart

Index: pkg/analysis_server/lib/src/utilities/change_builder_core.dart
diff --git a/pkg/analysis_server/lib/src/utilities/change_builder_core.dart b/pkg/analysis_server/lib/src/utilities/change_builder_core.dart
index c999300055d66e3977f6b7736165cf83cc10717a..9891a1ac91c92cb38930dcf22756bcc54996dcc2 100644
--- a/pkg/analysis_server/lib/src/utilities/change_builder_core.dart
+++ b/pkg/analysis_server/lib/src/utilities/change_builder_core.dart
@@ -72,6 +72,11 @@ class ChangeBuilderImpl implements ChangeBuilder {
     }
     return group;
   }
+
+  @override
+  void setSelection(Position position) {
+    _change.selection = position;
+  }
 }
 
 /**
@@ -95,6 +100,12 @@ class EditBuilderImpl implements EditBuilder {
   final int length;
 
   /**
+   * The offset of the selection for the change being built, or `-1` if the
+   * selection is not inside the change being built.
+   */
+  int _selectionOffset = -1;
+
+  /**
    * The end-of-line marker used in the file being edited, or `null` if the
    * default marker should be used.
    */
@@ -144,6 +155,11 @@ class EditBuilderImpl implements EditBuilder {
   }
 
   @override
+  void selectHere() {
+    _selectionOffset = offset + _buffer.length;
+  }
+
+  @override
   void write(String string) {
     _buffer.write(string);
   }
@@ -185,12 +201,19 @@ class FileEditBuilderImpl implements FileEditBuilder {
       : fileEdit = new SourceFileEdit(path, timeStamp);
 
   @override
+  void addDeletion(int offset, int length) {
+    EditBuilderImpl builder = createEditBuilder(offset, length);
+    fileEdit.add(builder.sourceEdit);
+  }
+
+  @override
   void addInsertion(int offset, void buildEdit(EditBuilder builder)) {
     EditBuilderImpl builder = createEditBuilder(offset, 0);
     try {
       buildEdit(builder);
     } finally {
       fileEdit.add(builder.sourceEdit);
+      _captureSelection(builder);
     }
   }
 
@@ -210,6 +233,7 @@ class FileEditBuilderImpl implements FileEditBuilder {
       buildEdit(builder);
     } finally {
       fileEdit.add(builder.sourceEdit);
+      _captureSelection(builder);
     }
   }
 
@@ -220,6 +244,7 @@ class FileEditBuilderImpl implements FileEditBuilder {
       builder.write(text);
     } finally {
       fileEdit.add(builder.sourceEdit);
+      _captureSelection(builder);
     }
   }
 
@@ -230,6 +255,7 @@ class FileEditBuilderImpl implements FileEditBuilder {
       builder.write(text);
     } finally {
       fileEdit.add(builder.sourceEdit);
+      _captureSelection(builder);
     }
   }
 
@@ -245,6 +271,18 @@ class FileEditBuilderImpl implements FileEditBuilder {
   }
 
   /**
+   * Capture the selection offset if one was set.
+   */
+  void _captureSelection(EditBuilderImpl builder) {
+    int offset = builder._selectionOffset;
+    if (offset >= 0) {
+      Position position =
+          new Position(fileEdit.file, offset + _deltaToOffset(offset));
+      changeBuilder.setSelection(position);
+    }
+  }
+
+  /**
    * Return the current delta caused by edits that will be applied before the
    * given [offset]. In other words, if all of the edits that have so far been
    * added were to be applied, then the text at the given `offset` before the